Chapter 10 Nutrition Strategies for Maximizing Performance
What are the recommendations for optimal muscle remodeling (hypertrophy)
- 20 to 30 grams of protein per meal - a higher-leucine protein meal at a frequency of every 3 to 4 hours
What does the optimal sports drink contain?
- 20 to 30 mEq of sodium (460 - 690 mg with chloride as the anion) per liter - 2 to 5 mEq of potassium (78-195mg) per liter - 5% to 10% of carbohydrate The ideal sports drink carbohydrate concentration is 6-8%. Anything greater than 8% may delay gastric emptying.
What is an essential source of energy in strength and power sports?
Muscle glycogen
What is exercise interference?
This is a concept suggesting that endurance exercise when combined with strength training back to back blunts gains in strength compared to pure strength training. Despite this, results show that there are improvements in endurance performance.
What is avoidance/restrictive food intake disorder (ARFID)
This is an eating or feeding disturbance that includes one or more of the following: - Apparent lack of interest in eating or food - avoidance based on the sensory characteristics of food - concern about aversive consequences of eating - significant weight loss - significant nutritional deficiency - marked interference with psychosocial functioning.
What is binge eating disorder?
This is eating significantly more food in a short period of time than most people would eat under the same circumstances. It's Characterized by repeated episodes occurring at least once a week for a period of three weeks, of uncontrolled binge eating.
What is anorexia nervosa?
This is self imposed starvation (excessive calorie restriction ) in an effort to lose weight and achieve thinness.
What are the recommendations for a pre-competition meal in endurance sports?
This is the most important meal for aerobic endurance athletes who compete in long-duration activity > 2hours, especially in the morning after an overnight fast. Carbohydrate consumption is recommended 3 hours before the endurance run. High Carbohydrate meal plus sports drink improves performance by 22% and consumption of sports drink only can improve performance to 9%
What is bulimia nervosa?
This is the recurrent consumption of food in amounts significantly greater than would customarily be consumed in a discrete period of time followed by episodes of purging. Purging follows episodes of binge eating and may include self induced vomiting, intense exercise, laxative use and diuretic use
Describe a commonly used carboloading regimen
Three days of a high carbohydrate diet in concert with tapering exercise the week before competition and complete rest the day before the event.
What is the primary purpose of the pre- competition meal?
To provide sufficient fluid to maintain hydration and carbohydrate and to maximize blood glucose and stored glycogen while also satisfying hunger.
According to the American Academy of Pediatrics, what are the recommendations on fluid consumption during practice?
- Children weighing 40kg (88 pounds) should drink 5 ounces of cold water or a flavored salted beverage every 20 minutes during practice. Adolescents weighing 60kg (132 pounds) should drink 9 ounces every 20 minutes even if they do not feel thirsty.
What are the benefits of consuming carbohydrates during aerobic endurance sports?
- Consuming carbohydrates during prolonged aerobic endurance exercise can improve performance while also reducing exercise-induced stress and suppression of immune system functioning.
How can energy requirements be estimated?
- Energy needs can be loosely estimated using the guidelines below: - Light activity Male(38) Female(35) (kcal/kg - Moderate activity Male (42) Female (37) (Kcal/kg) - Heavy Activity Male (50) Female (44) (kcal/kg)
Describe post competition nutrition in aerobic endurance events
- Glycogen synthesis occurs at a rapid rate when large amounts of carbohydrate - 1.5 g per kg body weight per hour - are consumed immediately after exercise or competition at regular intervals every 15 to 60 minutes thereafter for up to 5 hours. - At least 10 g of Protein should be consumed within 3 hours of exercise.
What are the benefits of a precompetition meal?
- Helps maintain hydration - provides carbohydrate to maximize blood glucose and glycogen stores - Keeps hunger pangs at bay
What are the weight (fat) loss guidelines for athletes?
- No difference between the amount of weight loss on a low carbohydrate diet as compared to a low fat diet. - Weight loss during dieting may come from muscle and caloric restriction may decrease muscle protein synthesis - Athletes should consume 1.8 to 2.7 g protein/kg of body weight per day in addition to maintaining a moderate energy deficit of approximately 500 calories per day.
What are the weight gain guidelines for athletes?
- The best time to focus on gaining weight is off season. - Generally, consume 500 additional calories per day - Eat enough protein to maximise gains in lean body mass: 1.5 to 2.0 g per kilogram body weight per day
What are the recommendations for post competition nutrition in strength and power sports
- athletes should focus in consuming higher glycemic carbohydrates immediately post-exercise if they must complete or train again over the course if the 24 hour period after their initial competition. Supplementing with protein after a muscle damaging bout of resistance training increases acute muscle protein synthesis.
What are potentially dangerous weight loss techniques?
- fasting - fad diets - voluntary dehydration ( diuretics, sauna, water and salt manipulation, wearing multiple layers of clothing etc - self induced vomiting - laxative abuse - inappropriate or excessive use of thermogenic acids
What are some of the results of rapid weight loss?
- fatigue - loss of lean body mass - headaches - mood swings - dehydration - heat illness - reduced muscle strength - hormone imbalances - kidney failure from diuretics abuse
What are the benefits of post-competition nutrition?
- helps athletes re hydrate, replenish glycogen restore and repair muscle tissue. - more salt can be added to foods when sweat sodium losses are substantial - High GI foods consumed after exercise may replenish glycogen faster than low GI foods. - although emphasis is usually placed on carbohydrate, in practical terms, consuming a balanced meal ensures the availability of all substrates for adequate recovery including amino acids.
What are the effects of carbohydrate consumption before and during strength and power competition in athletes?
- maintain glycogen stores - may decrease muscular fatigue in slow-twitch fibers - possibly lead to better performance
What factors influence energy requirements?
- resting metabolic rate - thermionic effect of food - physical activity - genetic
What are ways to minimize gastrointestinal issues pre-competition?
- try food in practice - when the meal is closer in time to the start of the game or event, consumer smaller amounts if food and liquids - Avoid high-fat and high-fiber foods. These both slow down digestion, which mat result in stomach cramps. - Avoid sugar alcohols. Consumption can cause gas, bloating, cramping and a laxative effect.
What are the symptoms of Anorexia Nervosa?
-Brittle hair and nails - dry and yellow skin - growth of fine hair all over the body (lanugo) - mild anemia and muscle wasting and weakness - severe constipation - brain damage - multiorgan failure - brain damage - infertility
What are some factors associated with binge eating disorder?
-Eating much more rapidly than normal - eating until uncomfortably full - eating large amounts of food when not feeling physically hungry - eating alone because of feeling embarrassed by how much one is eating - feeling disgusted with oneself, depressed or very guilty afterward
What is the equation for BMI?
1. Weight(Kg)/ Height (m2) 2. [Weight(pounds)/Height (inches^2] *703
What are the recommendations for protein consumption post competition in strength and power sports?
20-25 g of high quality, high leucine _______ for younger individuals and 40 g or more of _______ for older adults.
What are the recommendations for carbohydrate loading?
8-10g of carbohydrates/kg of body weight 10-12 g of carbohydrates/kg of body weight 36-48 hours before a marathon The goal is to increase muscle glycogen stores 20 - 40% The main challenge in females appears to be their overall insufficient daily calories intake
What are the nutritional recommendations for the hours leading up to competition in endurance athletes?
>1 hour - 0.5g carbohydrate per kilogram of body weight. 2 hours - 1g carbohydrate per kilogram of body weight. if not adequately hydrated, sip on 3-5 ml of fluid per kilogram of body weight 4 hours or more - 1-4g of carbohydrate per kilogram of body weight and 0.14-0.25g of protein per kilogram of body weight. Consume approximately 5-7 ml of water or a sports drink per kilogram of body weight.
What is carbohydrate loading?
A technique used to enhance muscle glycogen before aerobic endurance events as depletion in muscle and liver glycogen leads to fatigue during competition.
How much carbohydrates should aerobic endurance athletes consume?
Aerobic endurance athletes should consumer 30-90 g of carbohydrates each hour during prolonged aerobic endurance activity.
Carbohydrate loading
An effective strategy to maximize glycogen storage. However, athletes must consumer 8 to 10 g carbohydrate per kilogram body weight per day during the loading period to notice any benefit from carbohydrate loading.
What is the BMI for being obese?
BMI >30
What is the BMI for being 'overweight'?
BMI of 25 to 29.9
Why should athletes hydrate several hours before exercise?
Because doing this allows for fluid absorption and urine output before competing.
How is energy measured?
Energy is commonly measured in kilocalories (kcal). Energy caloric requirement is defined as energy intake equal to expenditure, resulting in constant body weight.
What are the recommendations for carbohydrates consumption post competition in strength and power sports?
In general 5-6 g/kg of body weight per day. At least 30 g Higher GI after training may reduce muscle breakdown. This is particularly important if the next event is within 24 hours
What are the effects of being overweight and obese?
Increases risk of morbidity: - hypertension - dyslipidemia - coronary heart disease - gallbladder disease - stroke -type 2 diabetes - respiratory problem - endometrial, breast, prostate and colon cancers
What are the effects of inspiring carbohydrates without ingestion in aerobic endurance exercise?
It has been found that simply rinsing carbohydrates through the mouth without actually ingesting seems to improve performances lasting 1 hour or so by 2 % to 3%, presumably affecting the central nervous system.
What is BMI?
It is a measure often used to assess risk for diseases that are associated with more body fat. It is simply a measure of excess wight and cannot distinguish between excess fat, muscle mass or bone mass.
Can BMI be used as an initial tool?
No, BMI should not be used as an initial screening tool but instead as an initial screening tool to identify potential weight issues in individuals and to track population-based rates of overweight and obesity.
What are the characteristics of people with Bulimia?
People with this disorder feel a lack of control over their eating during binge episodes. They are more likely to be normal weight as opposed to underweight, are unhappy with their weight and body and fear weight gain.
What are intermittent high intensity sports?
These are activities that include repeated bouts of short duration, high intensity activity in addition to a wide range of skills. Examples are: Soccer tennis basketball The provision of both fluids and carbohydrates is essential for performance during prolonged intermittent sports the effects of carbohydrates on performance may also depend on whether or not the athlete is competing in a fed or fasted and glycogen-depleted state.
What are the recommended fluid intake for tennis as a intermittent high intensity sport?
Tennis players should have 200-400 ml fluid per changeover with some of this fluid from a carbohydrate electrolyte sport drink.
What are the effects of consumption of carbohydrate after endurance exercise and pre lift?
The consumption of this macro-nutrient post-competition endurance sports can help suppress skeletal muscle breakdown.
What should be the initial goal for overweight and obese population when trying to lose weight?
The goal is to get a 10% weight loss within 6 months
What does proper hydration during competition prevent?
it is essential for performance during competition to prevent overheating, dehydration and heat illness
What are some symptoms of bulimia?
symptoms of this disorder are: - chronically inflamed and sore throat -swollen salivary gland sin the neck and jaw area - worn tooth enamel, increasingly sensitive and decaying teeth as a result of exposure to stomach acid - acid re-flux disorder and other gastrointestinal problems - intestinal distress and irritation from laxative abuse. - severe dehydration from purging of fluids
